Kate from what you've written about your childhood, and with the benefit of hindsight, you probably should have had professional psychotherapy many years ago - not counselling, hypnotherapy, self-help, etc.
Long-term trauma and damage can't be undone with positive thinking and a bit of a chat - but proper psychotherapy can take many years of treatment.
I'm far from an expert but your tremor sounds functional rather than essential, so might be managed with a course of CBT, which could get you over the practical problem of dealing with the shakes.